MATLAB 2D and 3D Plotting 5

Question 1

Which MATLAB function creates a quiver (vector field) plot?

Accepted Answer

quiver

Answer

quiver(x,y,u,v) draws arrows at (x,y) with direction and magnitude given by (u,v), used to visualize 2D vector fields.

Question 2

In MATLAB, how do you make a plot line semi-transparent with 50% opacity?

Accepted Answer

Set the line handle's 'Color' property to include an alpha value: [r g b 0.5]

Answer

In MATLAB, transparency for line objects is set via the Color property using a 4-element [R G B Alpha] vector where Alpha ranges from 0 (transparent) to 1 (opaque).

Question 3

What does the 'shading interp' command do to a surface plot in MATLAB?

Accepted Answer

Removes the mesh lines and applies smooth color interpolation across each face

Answer

'shading interp' removes the mesh edge lines and smoothly interpolates colors across each face using vertex color values.

Question 4

Which function in MATLAB plots a filled 2D polygon given vertex coordinates?

Accepted Answer

fill

Answer

fill(x,y,c) creates a filled 2D polygon by connecting the x and y coordinates and filling with color c.

Question 5

When using 'surf(X,Y,Z)' in MATLAB, what must be true about X, Y, and Z?

Accepted Answer

X and Y must be 2D grids (from meshgrid) and Z must be a 2D matrix of the same size

Answer

surf() requires X and Y to be 2D coordinate grids (typically from meshgrid) and Z to be a 2D matrix of the same size giving the height at each grid point.

MATLAB - MATLAB Technical Computing Practice Test

MATLAB - MATLAB Technical Computing Practice Test

MATLAB 2D and 3D Plotting 5